Automatic rotary drilling control



Aug. 14, 1962 J. LANGFORD AUTOMATIC ROTARY DRILLING CONTROL 2 Sheets-Sheet 1 Filed Nov. 29, 1957 Jf/PREL LAA/GFDRD, INVENTOR.

BY W

1962 J. LANGFORD 3,049,339

AUTOMATIC ROTARY DRILLING CONTROL Filed Nov. 29. 1957 2 Sheets-Sheet 2 United States Patent Ofitice 3,049,339 Patented Aug. 14, 1962 3,049,339 AUTOMATIC ROTARY DRELLING CONTROL Jerrel Langford, Odessa, Tex., assignor to Drill-O-Matic, Inc, Odessa, Tex., a corporation of Texas Filed Nov. 29, 1957, Ser. No. 699,583 13 Claims. (Cl. 254173) This invention pertains to well drilling and moreparticularly to an automatic control device for maintaining a constant pressure on the drill bit.

In the drilling of deep holes such as oil wells, it is desirable to keep a constant, predetermined load upon th drill bit. There are in existence today gauges by which the pressure on the drill bit may be determined from the tension in the dead line. Therefore, the pressure on the bit may be maintained manually by the use of such a gauge. Also, there are known today, and commonly on the market devices which have a power output which is responsive to the pressure on the drill bit as measured through the dead line. Therefore, the power output of such a control mechanism may be utilized for the operation of an automatic drilling control device.

I have invented such an automatic drilling control device.

It is an object of this invention to provide a device for automatically regulating the pressure on the drill bit.

Another object is to achieve this regulation of pressure on the drill bit with a portable device which may readi y be moved from one drilling rig to another.

Another object of this invention is to regulate the pressure on the drill bit with a device which is safe for the workmen to operate.

A further object of this invention is to provide an automatic regulator for drill bit pressure that is fail-safe, i.e. if any element or portion of the device breaks or fails, the device will be in a safe condition not causing injury to workmen or equipment.

A further object of this invention is to provide such a device which may be quickly and safely placed in an inoperative position when it is desired to manually control the drill bit.

Still further objects are to achieve the above with a device that is sturdy, simple, and reliable, yet :cheap and easy to manufacture.

The specific nature of the invention as well as other objects, uses, and advantages thereof will clearly appear from the following description and from the accompanying drawing, in which:

FIG. 1 is a schematic representation of an oil drilling rig with an automatic control in accordance with this invention.

FIG. 2 is an elevational View of the device in accordance with this invention showing only the portions at or about the drilling floor.

FIG. 3 is an elevational view showing the automatic controlling unit.

FIG. 4 is an end View partially in section taken on line 44 of FIG. 3.

As seen in the accompanying drawing, the invention is designed to be used in connection with a rotary drilling rig which has a derrick It The drilling floor 12 is also a portion of the rig. At the top of the derrick is the crown block 14 and suspended within the derrick is the travelling block 16. These two blocks are reeved together with the drilling line 18. One end of the drilling line is made fast to a portion of the derrick or drilling floor and this portion 20 is known as the dead line. Mounted on the drilling floor with suitable power units for rotating it when desired is a drawworks, the principal element of which is Windlass drum 22. The other end of the drilling line is wound on the drum and is known as the drum line 24'. The drum has associated with it a band type brake 26. The brake is a common type brake and is applied by applying tension to band 28. This application of tension is accomplished by means of a brake lever 30. The brake lever 30 extends in a generally horizontal position and is pivoted at one end. Adjacent to the pivot is a short bell crank extending upward to which is attached the brake band. As may be seen, downward movement of the brake lever will cause tension to be applied to the band; therefore retarding the rotational movement of the drum. Or, upward movement of the lever will release the brake, permitting the drum to ID- tate freely. Depending from the travelling block through the various elements well known to the drilling art is the drill stem 32-. It is on the lower end of the drill stem that the drill bit is attached.

Also well known to the drilling art are drill bit pressure indicators such as shown at 34. Actually these indicators measure the tension in the dead line 20. However, knowing the weight of the drill stem attached to the travelling block and knowing the mechanical advantage obtained by the number of turns the drilling line has on the crown and travelling blocks, it is possible to determine from the tension of the dead line what the weight or pressure on the drill bit is. Also, controllers 36 are well known to the art. These units also determine what the pressure on the drill bit is by measuring the tension on the dead line. However, they not only determine this pressure but interpret it so that if the pressure on the drill bit is less than a predetermined value, power is supplied to power lines 38, so that additional drilling line may be payed oil the drum lowering the drill bit, thereby increasing the pressure on it. Power may be either electrical power or air power. Controllers using either type of power are well known to the art. If electrical power is used, when the pressure on the drill bit was less than the predetermined amount, the power lines 38 would be energized by supplying them with electrical energy. If the lines were air lines, when the pressure on the drill bit became less than desired, they would be energized by increasing the air pressure therein.

The elements described above, that is the derrick, the travelling block, the Windlass drum, the brake, the drill stem, the drill bit pressure indicator, and the drill bit controller are all well known to the art, both individually and in the combination described above and as such form no part of this invention. This invention pertains to the self-contained automatic controlling unit 40.

Unit 40 has a frame 42 which is attached to the drilling floor 12. When thus attached, the frame 42 may be considered a portion of the derrick frame. Upon this frame is mounted a motor 44 which may be either air or electric, according to the type power supplied, so that when power is supplied to it from the control unit, the motor runs. Attached to the motor is a gear reduction unit 46. Also mounted on the frame is the motor pulley 48 which is driven from the gear reduction unit in such a way that the rotational speed of the motor pulley when the motor is running is approximately 90 revolutions per minute. Arm 50 is pivoted to the frame 42. Rotatably mounted to the end of the arm is drum pulley 52. The frame 42 is attached to the drilling floor in such a spaced relationship that the arm 50 makes a slight angle below the horizontal when the belt over drum pulley 52 contacts the drum flange 23 of the windlass drum 22. Suspended from some overhead portion of the derrick is free pulley 53. Line 54, reeved in pulley 53, connects weights 55 to idler pulley 56. Control line pulley 58 is also depended from some overhead portion of the derrick. A control line 60 is reeved through this pulley, one end of which is detachably connected to the end of the brake lever 30 while the other end is attached to control pulley 62. Thus the control pulley is mounted for translational as well as rotational movement. The axis of all six pulleys are parallel to one another and parallel to the axis of the drum 22. Also motor pulley 48, drum pulley 52, free pulley 53, control line pulley 58 and control pulley 62 are grooved so that they are actually sheaves. An endless V-belt 64 is reeved around motor pulley 48, idler pulley 56, drum pulley 52, control pulley 62 and back to motor pulley 48 in sequence. Also a weight 66 is hung from the end of brake lever 39. Weight 66 is decidedly heavier than weight 55. It may be seen that the weights pull the drum pulley toward the drum so that there is a frictional drive means from the drum to belt 64.

Thus I have provided a dilferential control unit. If the motor pulley 48 is rotating in the direction of arrow A at a faster peripheral speed than the peripheral speed of surface 23 of the drum in the direction of arrow B, then the length of belt between the pulleys 52 and 48 will be decreased along pulley 62. Therefore, the pulley 62 will have a translational movement toward pulleys 52 and 48 or downward. Through control line 60, this movement lifts brake lever 30 releasing the brake. Pulley 56 moves away from the pulleys 48 and 52, however, as the sole purpose of this pulley is to keep slack from the belt 64, this movement is not important. If the peripheral speed of surface 23 exceeds the peripheral speed of pulley 48, then the pulley 62 is free to move upward. The weight 66 will then move lever 30 downward and apply the brake.

With study, it may be seen that the device is failsafe. If the control line 60 or belt 64 breaks, the weight 66 applies the brake preventing excessive weight on the bit. If the belt should slip on surface 23, or if the power in lines 38 should fail, the brake is applied. A switch may be attached to weight indicator 34, so that if the bit pressure should get too high, the lines 38 may be opened, therefore providing a safety factor for a faulty controller 36.

At certain times, it is desirable to manually control the system; for example, when adding another drill stem to the string. By rotating arm 50 counter-clockwise, as seen in the drawing, lock bar 68 will be pulled by spring 70 against stop 72 on bar 50. The automatic system 40 is then inoperative until the lock 68 is manually raised. The weight 66 and control line 60 may be disengaged from lever 30 if desired.

It will be apparent that the embodiments shown are only exemplary and that various modifications can be made in construction, materials, and arrangement within the scope of the invention as defined in the appended claims.

I claim as my invention:

1. In a drilling rig having a derrick frame, a crown block at the top of the derrick, a travelling block within the derrick, a drilling line reeved between the crown block and travelling block, one end of the drilling line being the dead line which is attached to the foot of the derrick, a windlass drum mounted for rotation on the derrick floor, the other end of the drilling line being the drum line which is wound on the windlass drum, a brake on the windlass drum, and controller means for producing a power output responsive to the tension on the drilling line, the improvement comprising: an endless belt, frictional drive means for driving the belt from said windlass drum, a motor connected to the power output of said controller means, a motor pulley drivingly connected to the output of the motor, the endless belt passing over the motor pulley, and a control pulley mounted for rotational and translational movement, the control pulley connected to said brake, the endless belt passing over the control pulley, so that differential peripheral movement of the motor pulley and windlass drum causes translational movement of the control pulley and hence the brake.

2. The invention as defined in claim one, wherein said frictional drive means for driving the belt from said windlass drum includes an arm pivoted to the derrick frame, a drum pulley rotatably mounted on said arm, a flange on said windlass drum, said endless belt passing over said drum pulley, then contacting the windlass drum flange, and then passing over the control pulley and the motor pulley in sequence.

3. The invention as defined in claim one with the addition of means for taking up the slack caused by translational movement of said control pulley from said endless belt.

4. The invention as defined in claim two with the addition of means for taking up the slack caused by translational movement of said control pulley from said endless belt.

5. The invention as defined in claim four wherein said means for taking up the slack from said endless belt includes an idler pulley running on said belt between said motor pulley and said drum pulley.

6. The invention as defined in claim one with the addition of means for disconnecting said control pulley from said brake and means for inactivating said frictional drive means from said windlass drum.

7. The invention as defined in claim two with the addition of means for disconnecting said control pulley from said brake and said arm being capable of rotational movement away from said windlass drum so that said endless belt no longer contacts said drum flange.

8. The invention as defined in claim seven with the addition of a lock on the derrick frame adjacent to the arm so that the drum pulley may be locked away from the windlass drum.

9. In a drilling rig having a derrick frame, a crown block at the top ef the derrick, a travelling block within the derrick, a drilling line reeved between the crown block and travelling block, one end of the drilling line being the dead line which is attached to the foot of the derrick, a windlass drum mounted for rotation on the derrick floor, the other end of the drilling line being the drum line which is wound on the windlass drum, a brake on the windlass drum, and controller means for producing a power output responsive to the tension on the drilling line, the improvement comprising: a motor mounted on the derrick frame; the motor connected to the power output of said controller means; a motor pulley drivingly connected to the motor; a control pulley mounted for translational and rotational movement relative to the derrick; means for transmitting the translational movement of the control pulley to the brake; and an endless belt frictionally contacting the motor pulley, the control pulley and the windlass drum, so that ditferential peripheral movement of the motor pulley and windlass drum causes translational movement f the control pulley and hence the brake.

10. In a drilling rig having a derrick frame, a crown block at the top of the derrick, a travelling block within the derrick, a drilling line reeved between the crown block and travelling block, one end of the drilling line being the dead line which is attached to the foot of the derrick, a windlass drum mounted for rotation on the derrick floor, the other end of the drilling line being the drum line which is wound on the windlass drum, a brake on the windlass drum, and controller means for producing a power output responsive to the tension on the drilling line, the improvement comprising: a motor pulley rotatably mounted to derrick frame, means for rotating said motor pulley responsive to the power output of said controller means, an idler pulley depended from the derrick, the idler pulley being biased upward, an arm pivoted to the derrick frame, a drum pulley mounted on the end of the arm, the drum pulley being adjacent said windlass drum, a control pulley depending from a control line, the control line connected to said brake, bias means for urging the brake in the opposite direction of said control line,

and an endless belt frictionally contacting the elements in this sequence, from the motor pulley to the idler pulley, to the drum pulley, to the Windlass drum, to control pulley and back to the motor pulley, all of the axes of said pulleys being parallel to the axis of the drum, so that differential peripheral movement of the motor pulley and Windlass drum causes translational movement of the control pulley and hence the brake.

11. The invention as defined in claim ten wherein said control line and said bias means for urging the brake are readily detachable from said brake.

12. The invention as defined in claim ten with the addition of a lock bar pivoted to the derrick frame, a spring biasing the lock bar toward the end of the arm, the arm extending both ways from the arms pivot, the lock bar resting on the other end of the arm from that to which is attached the drum pulley.

13. In a drilling rig having a derrick frame, a crown block at the top of the derrick, a travelling block within the derrick, a drilling line reeved between the crown block and the travelling block, one end of the drilling line being the dead line which is attached to the foot of the derrick, a Windlass drum mounted for rotation on the derrick floor, the other end of the drilling line being the drum line which is wound on the Windlass drum, a brake on the Windlass drum, and controller means for producing a power output responsive to the tension on the drilling line, the improvement comprising: an endless belt, first drive means for driving the belt from said windlass drum, a motor connected to the power output of said controller means, second drive means connected to the output of the motor, the endless belt passing over said second drive means, and a control pulley mounted for rotational and translational movement, the control pulley connected to said brake, the endless belt passing over the control pulley, so that difierential peripheral movement of the second drive means and Windlass drum causes translational movement of the control pulley and hence the brake.

References Cited in the file of this patent UNITED STATES PATENTS 20 2,126,189 Goldman Aug. 9, 1938 2,783,968 Bell Mar. 5, 1957 FOREIGN PATENTS 995,410 France Aug. 22, 1951 

